As a technique for rendering a blood flow in a capillary of a tissue or in an equivalent functional vasculature, a technology relevant to a diagnosis support function for CT perfusion has been disclosed in non-patent document 1. Specifically, multiple ROIs are set in each of functional images obtained by performing CT perfusion. A difference of a mean value or a standard deviation of a blood-flow parameter (a cerebral blood flow (CBF), a cerebral blood volume (CBV), or a mean transit time (MTT)) within each of the ROIs is assessed in order to determine whether an object part (ROI) is an affected part.
Non-patent document 1: “Development of CT perfusion diagnosis support function (multi transparency view)” (journal of Japanese Society of Radiological Technology, Vol. 59, No. 9, p. 1032&22)
However, the present inventor et al. have noticed a problem, which will be described below, as a result of discussion on the prior art. Specifically, in the related art 1, ROIs are manually set. At this time, subject is reflected on setting of ROIs. Unless the ROIs are accurately disposed, the results of analysis are likely to be erroneous.